Protection of systems of distribution



0.3. RUSHMORE.

PROTECTION OF SYSTEMS 0F DISTRIBUTION. nrmcmou FILED MAR-ZhISIB.

1,386,898. Patented Aug. 9,1921.

Inventor-z David BFlushmory We Hisafittorney UNITED STATES DAVID B. RUSHMORE,,OF SCHENECTADY, NEW YORK, ASSIGNJOR TO GENERAL ELEC- TRIO COMPANY, AGORPORATION OF NEW YORK.

PATENT OFFICE.

PROTECTION OF SYSTEMS OF DISTRIBUTION.

Specification of Letters Patent.

Patented Aug. 9, 1921.

Application filed March 21, 1918. Serial No. 223,682.

To all whom it may concern Be it known that I, DAVID B. RUsHMonn, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented'certain new and useful Improvements in the Protection of Systems of Distribution, of which the fol lowing is a specification.

My present invention relates to electrical distribution systems and has for one of its objects the protection of'such systems and the apparatus connected thereto from dam- I used methods lies in the fact that further abnormal conditions may be set up in the system when the ground isremoved by reason of the sudden breaking of the current flowing in the ground connections.

A more specific ,object ot' my invention is to provide means for placing a low resistance ground upon a conductor which is affected by abnormal conditions and after a short period changing this to a high resistance ground and thenremoving it altogether. The particular low resistance grounding means which I prefer to employ is a stream of conducting liquid such as water with some salt dissolved therein in such amount as to make it a fairly good conductor. In carrying my invention into effect I associate with the distribution system to be protected a device for bringing into action a mechanism for producing a stream or jet of the conducting liquid whenever'certain abnormal conditions occur in the system. 'The mechanism for producing the stream-or jet of conducting liquid may be so arranged that after a time theconductivity of the liquid may be lowered by mixing water with the conducting .7 liquid and finally a stream of water" alone may be substituted for the conducting liquid. 'The device for bringing into 'action'this mechanism may assume a great variety of forms, depending upon the particular abnormal condition in the system against which protection is desired. For the purpose of describing my invention without limiting it to the particular use illustrated, I have shown how it may be carried into effect by means of an electromagnetic relay which is rendered operative by an unbalancing of the potential in the different conductors of the distribution system.

The novel features which I believe to be characteristic of my invention are set forth with particularity in the appended claims. The invention itself, however, together with further objects and advantages thereof will best be understood by reference to the following description taken in connection with the accompanying drawing in which Figure 1 shows diagrammatically one way in which my invention may be carried into effect, and Fig. 2 shows in somewhat greater detail a mechanism for producing the stream of liquid for grounding the distribution system.

As indicated in the drawing, a liquid container 1 is provided which is divided into compartments 2 and 3, compartment 2 being supplied with the conducting liquid and compartment 3 with water. Valves 4 and 5 control the flow of liquid from the two compartments and when these valves are opened the contents of the compartments are discharged through the nozzle 6 which is grounded at 7. A conductor 8 of any desired shape is so located that a stream issuing from the nozzle 6 will impinge upon it. The conductor which is to be grounded is connected to conductor 8 and hence when a stream of conducting liquid impinges upon the conductor 8 a low resistanee clrcuit between conductor and ground is closed through the jet, nozzle 6 and ground connection 7. Valves 4 and 5 are operated by means ofa plunger 9 which is normally held in the position shown in Fig. 2 by the spring 10 which draws the projection 11 up against the tripping mechanism 12. This tripping mechanism is operated by means of a solenoid 13. When the solenoid is energized the plunger is released and drawnupward by the spring 10. When it moves upward it lifts the valve 4 and allows a stream of the conducting liquid to flow out of the nozzle 6. To provide for the automatic closing of the valve 4 after a predetermined desired period, I may employ a solenoid ll which, when energized, will act in opposition to the pull of the spring 10 and pull the plunger 9 down. The winding of solenoid 14 is energized by a battery 15 and in the normal condition of the apparatus the circuit of this winding is open. hen the plunger 9 is raised, however. the projection 16 thereof engages one of the projections on the cams 17 and turns the snap switch 18, thereby closing the circuit to energize the winding of solenoid 11. During the upward movement of plunger 9, the projection 19 passes over the projection on cam 20 and hence does not operate snap switch 21. As soon as the circuit of solenoid 1% is closed the plunger starts to descend butits movement is retarded in any desired way by means of a dashpot 22 or any other suitable retarding mechanism. In the downward movement of the plunger the projection 19 will engage one of the projections on cam 20 and operate the snap switch 21 thus opening the circuit of the winding of solenoid 1-1 and arresting the downward movement of the plunger. Before this occurs, however, the plunger will have moved far enough to allow valve l to close and for the projection to press down the lever arm 24, which is pivoted at 25, and thereby open valve 5, allowing water to escape from the nozzle 6. The apparatus may be so adjusted that valve 5 starts to open before valve 1- is entirely closed and as a result the water will mingle with the concuctingfluid in a gradually increasing proportion until the valve l is entirely closed. In this way the conductivity of the stream issuing from the nozzle 6 will gradually be decreased from a maximum to a minimum. hen the circuit of solenoid ll is opened the plunger 9 will be drawn upward by the spring 10 until held by the tripping mechanism 12. During this upward movement valve o will be closed and the stream of water from nozzle 6 interrupted. The device will then be ready for another operation. In case solenoid 13 is still energized the operation described will of course be immediately repeated and the successive operations will continue as long as the solenoid 13 remains energized. It will of course be apparent that by varying the design and adjustment of the stream producing means, it will be possible to produce a stream of any constituency desired for any length of time desired and to vary the conductivity of the stream in any way desired.

In Fig. 1 I have shown one manner in which my invention may be applied for the protection of a distribution system comprising a source of'alternating current 26which supplies the primary 2? of a transformer 28.

The secondary 29 of this transformer fur nishes current to distribution conductors 30, 31 and 32. Since in some cases it will be desirable to ground only one conductor, I have provided a separate grounding means such as that shown in Fig. 2 for each of the conductors 30, 31 and 32. In order to ground the particular conductor upon which an abnormal condition occurs, I may employ a selective electromagnetic relay 33 having three arms 3 1, 35 and 36 controlled respectively by solenoids 37, 3S and 39. The windings of these solenoids are energized by the secondary of t 'anst'ormers a0, a1 and 42; the primaries of these transformers are connected respectivelv to conductors 30, 31 and 32. Under normal conditions in the distribution system all of the solenoids exert an equal pull upon their respective arms of the relay and the contact member 43 eecupies the position shown. hen, however, by reason of the occurrence of some abnor mal condition in the system, the potential of one of the conductors falls below that of the others, the corresponding solenoid no longer exerts the same pull and is overpowered by the action of the other two so that the member 43 will strike one of the contacts 4 1, 15 or 16 and close the circuit of the tripping solenoid 13 of one of the grounding devices, thus causing the device to make a ground upon the conductor affected. This will relieve the portion of the system which is in trouble and the ditliculty may automatically clear itself as soon as the potential impressed upon the affected point is removed. If the trouble is not cleared the grounding device will continue to operate and the station attendant may be apprised of the fact that there is trouble upon the system and take such further steps as may be necessary to remove the trouble or disconnect the source of supply from the system before serious damage occurs.

\Vhile I have described only one way in which my invention may be carried into effect, I do not wish to be limited to the particular use shown, as it will be apparent to one skilled in the art that many modifications may be made in the circuit arrangements and structural details as well as in the uses for which my invention is employed without departing from the scope of the appended claims.

Vhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. The combination with a system of distribution of means for producing a stream of liquid of good conductivity to ground said system and means responsive to abnormal conditions in said system for causing said stream producing means to act to produce a stream.

2. The combination with a system of electrical distribution of means for producing a stream of liquid and means responsive to abnormal conditions in said system for causing said stream producing means to act to produce a stream of liquid of good conductivity.

3. The combination with a system of dis tribution of means for producing a stream of liquid, means responsive to abnormal conditions in said system for causing said stream producing means to act and means for varying the conductivity of the stream produced thereby.

at. The combination with a system of dis tribution of means for producing a stream of liquid, means responsive to abnormal conditions in said system for causing said stream producing means to act, means for varying the conductivity of the stream produced thereby and means for interrupting said stream after a predetermined time.

5. The combination with a system of distribution of means for producing a stream of liquid of good conductivity to ground said system, means responsive to abnormal conditions in the system for ausing said stream producing means to act and means for varying the conductivity of the stream produced thereby. 4 i

6. The combination with a system of distribution of means for producing a stream of liquid of good conductivity to ground said system, means responsive to abnormal conditions in the system for causing said stream producing means to act, means for varying the conductivity of the stream produced thereby, and means for interrupting said stream after a predetermined time and thereby removing the ground from said systom.

7. The combination in an apparatus of the class described of means for closing an electric circuit comprising means for producing a stream of liquid and means for gradually varying the conductivity of said stream.

8. The combination in an apparatus of the class described of means for closing and opening an electric circuit comprising means for producing a stream of liquid to close a circuit and means for gradually varying the conductivity of said stream, and means for interrupting the stream and thereby opening the circuit.

9. The combination in an apparatus of the class described of means for closing an electric circuit comprising means for producing a stream of liquid and means for varying the conductivity of said stream between maximum and minimum values.

10. The combination in an apparatus of the class described of means for closing and opening an electric circuit comprising means for producing a stream of liquid of good conductivity to close a circuit, means for varying the conductivity of said stream and means for interrupting the stream and thereby opening the circuit.

11. The combination with a system of distribution of means responsive to abnormal conditions in said system for closing a low resistance circuit between said system and ground, and means for automatically increasing the resistance of said circuit and opening it after a predetermined time.

In Witness whereof, I have hereunto set my hand this 19th day of March, 1918.

DAVID B. RUSHMORE. 

